Mother \Moth"er\, n. [Akin to D. modder mud, G. moder mold, mud,
Dan. mudder mud, and to E. mud. See Mud.]
A film or membrane which is developed on the surface of
fermented alcoholic liquids, such as vinegar, wine, etc., and
acts as a means of conveying the oxygen of the air to the
alcohol and other combustible principles of the liquid, thus
leading to their oxidation.
[1913 Webster]
Note: The film is composed of a mass of rapidly developing
microorganisms of the genus Mycoderma, and in the
mother of vinegar the microorganisms (Mycoderma
aceti) composing the film are the active agents in the
Conversion of the alcohol into vinegar. When thickened
by growth, the film may settle to the bottom of the
fluid. See Acetous fermentation, under
Fermentation.
[1913 Webster]

The Collaborative International Dictionary of English v.0.48:

mycoderma \my`co*der"ma\, n. [NL., from Gr. my`khs a fungus +
de`rma skin.]
1. (Biol.) One of the forms in which bacteria group
themselves; a more or less thick layer of motionless but
living bacteria, formed by the bacteria uniting on the
surface of the fluid in which they are developed. This
production differs from the zoogloea stage of bacteria by
not having the intermediary mucous substance.
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2. (Capitalized) A genus of microorganisms of which the
acetic ferment (Mycoderma aceti), which converts
alcoholic fluids into vinegar, is a representative. Cf.
Mother.
[1913 Webster] Mycologic

The Collaborative International Dictionary of English v.0.48:

Fermentation \Fer`men*ta"tion\ (f[~e]r`m[e^]n*t[=a]"sh[u^]n), n.
[Cf. F. fermentation.]
1. The process of undergoing an effervescent change, as by
the action of yeast; in a wider sense (Physiol. Chem.),
the transformation of an organic substance into new
compounds by the action of a ferment[1], whether in the
form of living organisms or enzymes. It differs in kind
according to the nature of the ferment which causes it.
Note: In industrial microbiology fermentation usually refers
to the production of chemical substances by use of
microorganisms.
[1913 Webster +PJC]
2. A state of agitation or excitement, as of the intellect or
the feelings.
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It puts the soul to fermentation and activity.
--Jer. Taylor.
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A univesal fermentation of human thought and faith.
--C. Kingsley.
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Acetous fermentation or Acetic fermentation, a form of
oxidation in which alcohol is converted into vinegar or
acetic acid by the agency of a specific fungus (Mycoderma
aceti) or series of enzymes. The process involves two
distinct reactions, in which the oxygen of the air is
essential. An intermediate product, acetaldehyde, is
formed in the first process. 1. C2H6O + O [rarr] H2O +
C2H4O
Note: Alcohol. Water. Acetaldehyde. 2. C2H4O + O [rarr]
C2H4O2
Note: Acetaldehyde. Acetic acid.
Alcoholic fermentation, the fermentation which saccharine
bodies undergo when brought in contact with the yeast
plant or Torula. The sugar is converted, either directly
or indirectly, into alcohol and carbonic acid, the rate of
action being dependent on the rapidity with which the
Torul[ae] develop.
Ammoniacal fermentation, the conversion of the urea of the
urine into ammonium carbonate, through the growth of the
special urea ferment. CON2H4 + 2H2O = (NH4)2CO3
Note: Urea. Water. Ammonium carbonate.
[1913 Webster]
Note: Whenever urine is exposed to the air in open vessels
for several days it undergoes this alkaline
fermentation.
Butyric fermentation, the decomposition of various forms of
organic matter, through the agency of a peculiar
worm-shaped vibrio, with formation of more or less butyric
acid. It is one of the many forms of fermentation that
collectively constitute putrefaction. See Lactic
fermentation.
enzymatic fermentation or Fermentation by an unorganized
ferment. Fermentations of this class are purely chemical
reactions, in which the enzyme acts as a simple catalytic
agent. Of this nature are the decomposition or inversion
of cane sugar into levulose and dextrose by boiling with
dilute acids, the conversion of starch into dextrin and
sugar by similar treatment, the conversion of starch into
like products by the action of diastase of malt or ptyalin
of saliva, the conversion of albuminous food into peptones
and other like products by the action of
pepsin-hydrochloric acid of the gastric juice or by the
ferment of the pancreatic juice.
Fermentation theory of disease (Biol. & Med.), the theory
that most if not all, infectious or zymotic disease are
caused by the introduction into the organism of the living
germs of ferments, or ferments already developed
(organized ferments), by which processes of fermentation
are set up injurious to health. See Germ theory.
Glycerin fermentation, the fermentation which occurs on
mixing a dilute solution of glycerin with a peculiar
species of schizomycetes and some carbonate of lime, and
other matter favorable to the growth of the plant, the
glycerin being changed into butyric acid, caproic acid,
butyl, and ethyl alcohol. With another form of bacterium
(Bacillus subtilis) ethyl alcohol and butyric acid are
mainly formed.
Lactic fermentation, the transformation of milk sugar or
other saccharine body into lactic acid, as in the souring
of milk, through the agency of a special bacterium
(Bacterium lactis of Lister). In this change the milk
sugar, before assuming the form of lactic acid, presumably
passes through the stage of glucose. C12H22O11.H2O -->
4C3H6O3
Note: Hydrated milk sugar. Lactic acid.
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Note: In the lactic fermentation of dextrose or glucose, the
lactic acid which is formed is very prone to undergo
butyric fermentation after the manner indicated in the
following equation: 2C3H6O3 (lactic acid) --> C4H8O2
(butyric acid) + 2CO2 (carbonic acid) + 2H2 (hydrogen
gas).
Putrefactive fermentation. See Putrefaction.
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